(maint) Fix typo in sync.yml
(maint) Fix typo in sync.yml

Previously in commit b56360e95dfa19ebfa24b5dd1035fdfe0c8b97c6 the sync.yml was
updated to include rubocop testing, however the yml was invalid due to missing
whitespace.  This caused the modulesync_configs testing to fail.  This commit
fixes the whitespace.

[skip ci]

puppetlabs/puppetlabs-concat